Welcome to the world of diversity.
Your all sentences can be used ok and has same meaning (for casual conversation at least)
But 사실을 인정해야겠어요 sounds most natural to me somehow.
1) 이만 집에 가야겠어요.
2) 이만 집에 가야 하겠어요.
3) 이만 집에 가야 되겠어요.
1) reads most natural.
2, 3) can be used ok but not sure if they are grammatically correct.
In many cases, shortest is the best answer:)